Prospect (and suspect) defense

For the last couple of years, Sean Smith and I have been publishing minor league defense numbers using his system, TotalZone. We ran an update using games through June 30, late enough to start giving us a clue as to which prospects are having good and bad years in the field.

As usual with fielding numbers, some caveats must be stated. These are estimates of performance, not statements of talent. If a player is +5 runs in the first of 2010, there’s no reason to believe he’ll be +5 in the second half—that’s like assuming a .400 hitter on May 1 will keep it up for another month. In any given year, a great fielder might post pedestrian numbers, and vice versa.

All that said, it’s fun to take a look at the leaderboards and find players who are having surprising years, or are building on already sterling records as solid fielders. Let’s start at the tough end of the defensive spectrum.

Shortstop

Two guys close to the top of the list may be of interest to more than just prospect-watchers. Cubs farmhand Darwin Barney is at 13 runs above average, while Brewers backup Luis Cruz sits at +10. Barney’s track record is strong, having posted a +16 year in 2008, and Cruz did him even better, a +18 two years ago.

In the “surprise” column at short is Astros youngster Brandon Wikoff, currently at +13. He posted solid numbers in a partial season last year, but my system for college players rated him as merely average throughout his career at Illinois.

Less of a surprise is Brandon Crawford, at +9 so far this year. He’s a favorite of my college system, having posted a +10 in his final NCAA season.

Center field

Two prospects are in the top 15 in center: Engel Beltre (+10) and Lorenzo Cain (+9). Beltre has been consistently above average; he hasn’t posted a negative number since his 18th birthday. Cain’s result is more headline-worthy. TotalZone liked him in 2006-07 (+27 and +12, respectively), but hated him last year (-15).

A wild card to keep an eye on is Julian Yan of the DSL Cardinals. The Dominican League didn’t even start play until mid-May, and Yan has had one-third the chances of Beltre, but he’s already amassed 10 runs above average. Yes, I agree, it’s ridiculous, and it’ll come back to earth. But … wow?!

The trailers are also prospect-packed. Ben Revere “leads” the way at -10, followed by D’Vontrey Richardson (-7) and Gorkys Hernandez (-7). And if we’re indulging in tiny DSL samples, I must mention Wagner Mateo, at -6 already for the DSL Diamondbacks.

Second base

Steven Singleton, a Twins farmhand, is far from a prospect, but is elite defense at second base enough to overcome a .750 minor league OPS? He posted +9 two years ago, +8 last year, and he’s now at +11 for Double-A New Britain.

A better prospect case can be made for Alexia Amarista, second on the list behind Singleton. His +9 is no surprise at all—last year he managed a whopping +20 in low-A. Color me impressed.

At the other end are two college players worth highlighting for very different reasons. Uber-prospect Dustin Ackley isn’t just underwhelming at the plate, he’s at -6 in the field. The defensive woes are more understandable, given he’s so inexperienced at second.

Less understandable is the -4 posted by Rays minor leaguer Tyler Bortnick. Bortnick probably doesn’t have a major league future, but the 2009 16th-round caught my attention as one of the best defenders at shortstop in the college ranks. Maybe the last few months are just a blip. His .850 OPS will certainly keep him around long enough to right the course.

Third base

Some solid seasons so far: the healthy Taylor Green at +6, Todd Frazier at +4, Matt Dominguez at +4 and Mike Hessman at +4. Dominguez has been all over the board (-6 in 2008, +8 last year), while Hessman is a consistent favorite of TotalZone. He’s generally considered a stereotypical quad-A power hitter, but his defense undermines that judgment.

Corner outfield

You can’t swing a Louisville Slugger without hitting a top prospect at the top of the TotalZone rankings for corner outfielders. Having a tremendous defensive season is one of the topmost prospects, Domonic Brown, at +11. Not far behind is Mike Stanton at +10.

Todd Frazier can pick it wherever he plays: He’s been good for +7 in left, a bit better than the likes of Caros Peguero and John Mayberry.

I can’t speak nearly as highly of Michael Taylor, who has been eight runs below average in right this year. Even worse: Caleb Gindl at -11. Gindl’s 5-foot-9 frame hasn’t held him back at the plate, but maybe it’s working against him in the field.

First base

Who cares about first base defense, right? Well, Pirates farmhand Matt Hague would appreciate it if you started caring. He struggled at the hot corner (-8 in limited time two years ago), but he has earned the approval of TotalZone, with +6 last year and a truly unbelievable +11 so far in 2010.

Brandon Belt has made a lot more noise with the bat, but has also been worth +4 in the field—pretty good for first baseman in the non-Hague category.

There aren’t many notable players very far from average at this position, but if we hunt, we find Koby Clemens at -3, Beau Mills at -3, Brett Wallace at -4 and Dayan Viciedo at -5. (Though Viciedo is also +3 at limited time at third. Key word in both cases: “limited.”)

Three months later

We’re still learning how to integrate defensive stats into our daily chatter about major leaguers. We’ve barely started figuring out how to include them in evaluations of minor leaguers.

This article is hardly an attempt to do so, but consider this a reminder that there’s more to position prospects than walk and strikeout rates, arm strength and baseball instincts. Some guys end up being worth millions to their clubs on the basis of less toolsy defensive skills, and we’d do well to watch for those sorts of players in the years before they are finally called up.